JPH04283759A - Image forming device - Google Patents

Abstract

PURPOSE:To make a device small in size and light in weight, and also to reduce a manufacture cost by eliminating a metal-made reinforcing frame for holding functional parts. CONSTITUTION:The functional parts such as an optical system 3, an image forming part 4, a paper carrying part 5, a driving system 7 for driving them and an electrical equipment 8, etc., are held by an upper casing 24 and a lower casing 25 provided with desired rigidity and having a monocoque structure.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine or an electrostatic printer.

0002

[Prior Art] Conventionally, extremely small image forming apparatuses such as electrostatic copiers and printers have been used to visualize an electrostatic latent image formed on a photoreceptor drum into a toner image and then transfer it to paper. A so-called portable type device has been provided (for example, see Japanese Patent Publication No. 2-17453).

This type of image forming apparatus includes an image forming section that visualizes an electrostatic latent image corresponding to a document image formed on a photoreceptor into a toner image, and then transfers the toner image onto paper; A paper transport section that includes a fixing section that fixes an image, introduces paper into the apparatus main body, and discharges the paper from the apparatus main body after being supplied to the image forming section, a drive system that drives these, and control circuits and other electrical components. It is equipped with functional parts such as Each of these functional parts is placed inside a box-shaped casing made of a resin molded product, and is attached to a metal reinforcing frame made of a pair of side plates and stays that connect the side plates.
each installed.

0004

SUMMARY OF THE INVENTION In order to popularize the image forming apparatus having the above structure for home and personal use, it is desirable to reduce the size and weight as much as possible, and to reduce the manufacturing cost and selling price. However, conventional image forming apparatuses require a reinforcing frame to attach functional parts, which increases the number of parts, making it impossible to achieve a smaller size and lighter weight, and raising manufacturing costs. was there. Furthermore, extra man-hours are required to assemble the reinforcing frame, resulting in a further problem of higher manufacturing costs.

[0005] Furthermore, the smaller and lighter the device is, the more anyone can carry it freely, which increases the risk of the device being hit or dropped and subject to excessive impact. When an excessive impact is applied to the device in this manner, damage such as cracking or plastic deformation is likely to occur, particularly at the joint between the casing and the reinforcing frame due to the difference in material and strength between the two.

[0006] Therefore, it is conceivable to abolish the above-mentioned reinforcing frame, but in this case, the rigidity of the main body of the device decreases, so the influence of external forces on functional parts, which could not be a problem with the conventional structure, cannot be overlooked. It becomes a factor. In particular, the product concept of compact and lightweight image forming devices is to make them popular for home and personal use, and maintenance and inspections must be handled by users themselves, rather than by professional service personnel. There is. However, when a functional component ceases to function due to an external force, it is practically impossible for a user who cannot even discover that the cause is due to improper handling of the component to take measures on his own. Considering these points, eliminating the influence of external forces on functional components becomes an important requirement that cannot be avoided in portable image forming apparatuses.

The present invention has been made in view of the above points, and does not require a reinforcing frame, making it possible to achieve smaller size, lighter weight, and lower manufacturing costs.
An object of the present invention is to provide an image forming apparatus that can suppress the influence of external forces on functional components.

[0008]

[Means for Solving the Problems] The image forming apparatus of the present invention for achieving the above object has the following features: (1) Developing an electrostatic latent image formed on a photoreceptor into a toner image and then transferring it to paper; an image forming section, (1) a fixing section that fixes the toner image transferred to the paper, and which introduces the paper into the apparatus main body and discharges the paper from the apparatus main body through the image forming section; (2) a paper transport section that drives these. In an image forming apparatus that includes at least a drive system and (1) electrical components, and in which these functional components (2) to (3) are arranged in a casing made of a resin molded product, the casing is configured to have a monocoque structure and an upper casing that can be separated from each other. The device is characterized by comprising a lower casing and each casing holding the above-mentioned functional components.

[0009]

[Operation] According to the image forming apparatus having the above configuration, the upper and lower casings have a monocoque structure to ensure the desired rigidity, and since the functional parts are held by the casings, a conventional metal reinforcing frame is provided. Functional components can be placed inside the casing while suppressing the influence of external forces.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will now be described in detail with reference to the accompanying drawings. FIG. 2 is a perspective view of a copying machine as an image forming apparatus showing an embodiment of the present invention, and FIG. 3 is a schematic sectional view showing its internal configuration. The above-mentioned copying machine is a so-called moving table type that illuminates and scans a document placed on the document table 1 by moving the document table 1 made of a transparent glass plate in the left-right direction in FIG. A document presser 11 for holding down a placed document is provided above the document table 1 so as to be rotatable and openable. The copying machine includes an optical system 3 for illuminating and scanning a document moved by a document table 1, and a photosensitive drum 42, inside a device main body 2.
After the electrostatic latent image formed on the paper is visualized by the developing device 41, an image forming section 4 is arranged to transfer the toner image onto a sheet of paper, and a fixing section 6 is disposed in the middle to fix the toner image transferred to the paper. is introduced into the apparatus main body 2 from the paper feed port 26, and then the image forming section 4
A paper transport section 5 that discharges the paper from the paper discharge port 21 through the paper, a drive system 7 (see FIG. 9) for driving the document table 1, the image forming section 4, and the paper transport section 5, and a control circuit that controls these drives. It is equipped with functional parts such as electrical equipment 8 (see FIG. 9).

The optical system 3 includes a fluorescent lamp 31 for illuminating the original, a lens 32 for guiding light reflected from the original to the photosensitive drum 42, and the like, which are arranged inside a case 33. . The image forming section 4 includes a photosensitive drum 4
A charger 43, a developing device 41, a transfer charger 44, and a cleaner 45 are arranged in this order around the photoreceptor drum 42, and an original image is formed on the outer peripheral surface of the photosensitive drum 42, which is uniformly charged by the charger 43. After forming an image to form an electrostatic latent image, the electrostatic latent image is transferred to a developing device 4.
This is a conventionally known configuration in which a toner image is visualized by a toner imager 1, a toner image is transferred to paper by a transfer charger 44, and residual toner is collected by a cleaner 45. A developing device 41, a photosensitive drum 42, a transfer charger 44, and a cleaner 4 are components of the image forming section 4.
5 are each assembled into an image forming frame 46 (see FIG. 4) to form a unit. Further, the electrification charger 43 is held by the case 33 of the optical system 3. The image forming frame 46 is made of a resin molded product, and a cleaner 4 is attached to the image forming frame 46.
A toner collection container 47 for storing the toner collected by 5 is integrally formed. The toner collection container 47 has a rectangular tray-like planar shape, and is provided above the paper transport section 5 on the downstream side in the transport direction. This toner collection container 47 has an inclined side surface 47c continuous to a horizontal bottom 47b.
A flange 47a extending toward the paper discharge port 21 is formed continuously from the upper end of the flange 7c, and the lower surface of the flange 47a serves as an upper guide for guiding the upper surface of the paper that has passed through the fixing section 6. . Note that the flange portion 47a is in close contact with the upper edge of the paper ejection port 21 when it is introduced into the paper ejection port 21, and is designed to prevent the paper from getting caught on the upper edge. ing. In this way, since the lower surface side of the toner collection container 47 is used as an upper guide, there is no need to separately arrange an upper guide, and the number of parts and assembly man-hours can be reduced accordingly, making it possible to reduce manufacturing costs. can.

The developing device 41 includes a toner cartridge 41c that is removably inserted into a developing housing 41a made of resin, and a toner supply device that supplies toner dropped from the toner cartridge 41c into the inside of the developing housing 41a. roller 41d and developer housing 41a
A stirring roller 41e that stirs the toner supplied inside the
and a developing roller 4 that supplies toner to the photoreceptor drum 42.
1f. A large number of rib-shaped upper guides 41b are provided on the lower surface of the developing housing 41a and project in parallel to each other, and these upper guides 41b guide the upper surface side of the sheet being conveyed. The upper guide 41b is molded integrally with the developer housing 41a, and therefore, compared to the case where the upper guide is formed separately, the number of parts and assembly steps can be reduced, and manufacturing costs can be reduced.

The paper transport unit 5 has a pair of transport rollers 51 that sandwich the paper set in the paper feed tray 22 and introduce it into the apparatus main body 2, and a pair of transport rollers 51 that abuts the leading edge of the paper transported by the pair of transport rollers 51. , a registration stopper 52 for temporarily holding the paper on standby, and the fixing section 6. The upper roller 51a of the transport roller pair 51 is rotatably supported by an upper guide 41b that projects from the developing housing 41a of the developing device 41. That is,
The upper guide 41b also serves as a support member for the upper roller 51a. Further, the fixing unit 6 fixes the toner image transferred to the paper while sandwiching and conveying the paper, and includes a heat roller 61 heated by a built-in heater,
A pressure roller 62 that is pressed and driven by this heat roller 61
It is equipped with The pressure roller 62 is provided so as to be freely movable in the vertical and horizontal directions while being biased upward by a spring (not shown), and its support shaft 62a is introduced into the groove 63a of the stay 63 that supports the heat roller 61. By doing so, the relative position with respect to the heat roller 61 is determined. Further, the registration stopper 52 is rotatably provided around a fulcrum 52a, and is normally biased to rotate clockwise in FIG. The leading edge of the paper is brought into contact with the paper in this advanced state, and the paper is put on standby. Then, when the document table 1 has moved to a predetermined position, the registration stopper 52 is rotated counterclockwise via a link mechanism operated by the document table 1, for example, to retreat from the paper conveyance path, thereby making it standby. The paper thus prepared is supplied to the image forming section 4.

The casing of the apparatus main body 2 is composed of an upper casing 24 and a lower casing 25 that are separably screwed to each other, and include the optical system 3, image forming section 4, and paper conveying section as the above-mentioned functional components. 5, a drive system 7, and an electrical component 8 are held by an upper casing 24 and a lower casing 25, respectively. In further detail with reference to FIGS. 1, 9 and 10, the optical system 3
The case 33 is screwed to the upper casing 24, so that the entire optical system 3 is held by the upper casing 24. Further, the image forming frame 46 of the image forming section 4 is screwed to the upper casing 24, so that the developing device 41, the photosensitive drum 42, the transfer charger 44, and the cleaner 4 of the image forming section 4 are fixed to the upper casing 24 with screws.
5 is held in the upper casing 24. Further, the remaining charger 43 of the image forming section 4 is indirectly connected to the upper casing 2 through the case 33 of the optical system 3.
It is held at 4. Furthermore, the upper roller 51a of the pair of transport rollers 51 of the paper transport section 5 is connected to the developing housing 4.
1a, and the lower roller 51b and resist stopper 52 are held by a lower guide 25a, which will be described later, which is integrally molded with the lower casing 25, and the heat roller of the fixing unit 6 61 is held by the upper casing 24 via a stay 63, and the pressure roller 62 is held by the lower casing 25.

The lower casing 25 is made of a resin molded product, and as shown in FIGS. 5 and 10,
A large number of rib-shaped lower guides 25a are integrally molded on the inner bottom of the guide 25a to guide the lower surface side of the sheet being conveyed. Further, an opening 25b is provided at the bottom of the lower casing 25, and a support member 25d rotatable about a fulcrum 25c is introduced into the opening 25b. This support member 25d is made of a resin molded product,
On the upper surface side, a large number of rib-shaped lower guides 25e that guide the lower surface of the sheet being conveyed are integrally formed and arranged in parallel. By rotating this support member 25d clockwise in FIG. 3 about the fulcrum 25c, the lower casing 2
5 can be opened, thereby opening a part of the paper conveyance path to facilitate jam removal and the like. Note that the support member 25d includes a transfer charger 4, which is one of the components of the image forming section 4 described above.
4 is installed. Furthermore, the lower casing 2
5 is formed with a rib-shaped upright piece 25f along the peripheral edge of the opening 25b, and the lower casing 25 is made into a monocoque structure by this upright piece 25f and the lower guide 25a, etc., and the desired rigidity is achieved. It is secured. Note that cutouts 25g for forming a paper feed port 26 and a paper discharge port 21 are formed on both sides of the lower casing 25.

The upper casing 24 is made of resin and is integrally molded, and has cutouts 2 on both sides for forming a paper feed port 26 and a paper discharge port 21, as shown in FIG.
4a is formed, and an opening 24b for inserting and removing the toner cartridge 41c is formed on one side that intersects the both sides. In addition, a slit 24c for illuminating and scanning the original is formed on the upper surface, and a groove 24i for attaching a slider S (see FIG. 7) that movably supports one end of the original table 1; Projections 24j for supporting the other end of the document table 1 are formed, respectively. Further, inside the upper casing 24, a pair of band-shaped guide portions 24d are formed to hang down and guide the introduction of the toner cartridge 41c. The guide portion 24d is integrally molded at the same time as the upper casing 24, and is formed integrally with the toner cartridge 4.
It is formed along almost the entire length of 1c (see FIG. 9). Further, a lid portion 24e that covers the upper opening of the toner collection container 47 is formed at a location corresponding to the toner collection container 47. This lid portion 24e includes a top surface of the upper casing 24 and a frame-shaped hanging piece 24 extending downward from the top surface.
f, and the hanging piece 24
f in close contact with the upper opening edge of the toner collection container 47,
The toner collection container 47 is closed, thereby preventing the toner collected in the toner collection container 47 from scattering. Note that the toner collection container 47 and the upper casing 2
The lid portion 24e of No. 4 is connected with screws (not shown) so as to be in close contact with each other. As described above, since the lid part 24e is integrally molded on the upper casing 24, there is no need to form a separate lid on the toner collection container 47, which reduces the number of parts and reduces the number of assembly steps. be able to. Further, since the toner cartridge 41c can be inserted and removed through the opening of the upper casing 24, the replacement work can be easily performed without opening the inside of the apparatus main body 2. Moreover, the guide portion 24 guides the insertion and removal of the toner cartridge 41c.
Since d is integrally molded into the upper casing 24, there is no need to separately form the guide, and the number of parts and assembly steps can be reduced accordingly, which helps to reduce costs. And the upper casing 24
is constructed into a monocoque structure by the guide 24b, hanging piece 24f, etc., thereby ensuring desired rigidity.

Further, the upper casing 24 is integrated with the lower casing 25 by screwing them at connecting portions 24k and 25h formed at at least four corners of each. In this way, the upper casing 24
are screwed to the lower casing 25 at least at the four corners, so even if each casing 24, 25 is warped, this can be corrected and both can be accurately positioned, and the upper casing 24
Even if they are opened, there is no risk of local stress occurring between them. That is, when the upper casing 24 is pivotally supported relative to the lower casing 25 so as to be rotatably openable and closable to form a so-called clamshell type, the upper and lower casings 24,
If the 25 is warped, it will be difficult to accurately position the two, and local stress will be generated in the pivot portion, causing problems with durability. However, by using the above-mentioned screw fastening method, such problems can be avoided. can be avoided.

The opening 24b for inserting and removing the toner cartridge 41c is closed by a cover 24g fitted to the opening 24b. Further, the paper feed tray 22 and the paper discharge tray 23 that receives paper discharged from the paper discharge port 21 are rotatably attached to the lower casing 25, and are rotated upright when not in use. By doing so, it can be kept along the upper casing 24. Furthermore, the upper casing 2
4 and the lower casing 25 are preferably combined in a zigzag shape, as shown in FIG. This means that the light is transmitted from the abutting part of the two to the main body of the device.
This is because it is possible to effectively prevent the photosensitive drum 42 from being deteriorated by the intruding light. Note that a cursor for guiding the width of the paper may be provided on the paper feed tray 22 so as to be slidable and adjustable according to the width of the paper.

The drive system 7 is fixed to a drive system arrangement portion 24h formed inside the upper casing 24, as shown in FIG. This drive system 7 drives, in addition to the photosensitive drum 42, a toner supply roller 41d, stirring roller 41e, and developing roller 41f of the developing device 41, an upper roller 51a of the paper conveying section 5, a heat roller 61 of the fixing section 6, etc. These driven parts are each driven by a motor 71 via a gear mechanism 72. In addition, electrical components 8 having circuit boards etc. that control these drives are also included.
It is attached to the upper casing 24. By arranging the drive system 7 and the electrical components 8 together on the upper casing 24 side in this manner, the wiring for the drive system 7 and the wiring between the electrical components can be easily and efficiently performed. That is, when the drive system 7 and the electrical components 8 are arranged separately on the upper casing 24 side and the lower casing 25 side, both casings 24
, 25, and the wiring work cannot be done in a concentrated manner, which is time-consuming.
By arranging them together on the 4 sides, there is no need for crossover wiring between the two casings 24 and 25, and the wiring work can be concentrated on one casing side, making the work easier and more efficient. can be done.

As described above, according to the above embodiment, each functional component is held by the casings 24 and 25, which have a monocoque structure and ensure rigidity, so that external forces acting on the main body 2 of the device are not affected by the functional components. The impact can be suppressed. In particular, regarding important functional parts such as the image forming section 4,
The casing 24, 2 without significantly changing its form.
5, the inherent rigidity of the functional component itself can be fully demonstrated, and as a result, it can strongly withstand excessive external forces. therefore,
It can exhibit excellent durability even against fairly rough handling by general users.

It should be noted that the present invention can of course be applied and practiced not only to the above-mentioned moving table type copying machine but also to a type of copying machine in which a document is moved by a conveyance roller. Furthermore, the present invention can be applied not only to copying machines but also to electrostatic printers and the like.

[0022]

As described above, according to the image forming apparatus of the present invention, the upper and lower casings have a monocoque structure to ensure the desired rigidity. Can hold parts. Therefore, it can withstand fairly rough handling by general users.

Furthermore, since the conventional metal reinforcing frame is not required, the number of parts and the number of assembly steps can be reduced accordingly, making it possible to reduce the manufacturing cost and achieve a reduction in size and weight.

[Brief explanation of the drawing]

FIG. 1 is an exploded sectional view of a copying machine as an image forming apparatus of the present invention.

FIG. 2 is a perspective view of the copying machine.

FIG. 3 is a schematic cross-sectional view showing the internal configuration of the copying machine.

FIG. 4 is a plan view showing an image forming section frame and a toner collection container.

FIG. 5 is a perspective view showing the lower casing.

FIG. 6 is a perspective view of the upper casing.

FIG. 7 is a partially omitted cross-sectional view showing the upper casing and the document table.

FIG. 8 is an enlarged cross-sectional view showing a butted state of the upper casing and the lower casing.

FIG. 9 is a bottom view showing how the functional components are held by the upper casing.

FIG. 10 is a plan view showing how the functional components are held by the lower casing.

[Explanation of symbols]

1 Manuscript table 2　　　　　　　　Device body 3. Optical system 4 Imaging section 5 Paper transport section 6 Fusing part 7 Drive system 8 Electrical components 24 Upper casing 24e Lid part 24d Guide part 25 Lower casing 41c toner cartridge 47 Toner collection container

Claims (1)

[Claims] Claim 1: ■ An image forming unit that visualizes an electrostatic latent image formed on a photoreceptor into a toner image and then transfers it to paper;
A paper transport section that includes a fixing section that fixes the toner image transferred to the paper, introduces the paper into the apparatus main body, and discharges the paper from the apparatus main body through the image forming section, ■ A drive system that drives these, and ■ Electrical equipment. In the image forming apparatus, the functional parts (1 to 2) are arranged in a casing made of a resin molded product, and the casing is composed of an upper casing and a lower casing having a monocoque structure and separable from each other. , an image forming apparatus characterized in that each casing holds the above-mentioned functional components.